Why are so many kids getting myopia?

Myopia isn’t an infectious disease, but it has reached nearly epidemic proportions in parts of Asia. In Taiwan, for example, the percentage of 7-year-old children suffering from nearsightedness increased from 5.8 percent in 1983 to 21 percent in 2000. An incredible 81% of Taiwanese children are myopic. If you think that the consequences of myopia are limited to a lifetime of wearing spectacles—and, let’s be honest, small children look adorable in eyeglasses—you are mistaken. The prevalence of high myopia, an extreme form of the disorder, in Asia has more than doubled since the 1980s, and children who suffer myopia early in life are more likely to progress to high myopia. High myopia is a risk factor for such serious problems as retinal detachment, glaucoma, early-onset cataracts, and blindness.

Researchers believe they are now closing in on a primary culprit: too much time indoors. In 2008 orthoptics professor Kathryn Rose found that only 3.3% of 6- and 7-year-olds of Chinese descent living in Sydney, Australia, suffered myopia, compared with 29.1 percent of those living in Singapore. The usual suspects, reading and time in front of an electronic screen, couldn’t account for the discrepancy. The Australian cohort read a few more books and spent slightly more time in front of the computer, but the Singaporean children watched a little more television. On the whole, the differences were small and probably canceled each other out. The most glaring difference between the groups was that the Australian kids spent 13.75 hours per week outdoors compared with a rather sad 3.05 hours for the children in Singapore.

The unfortunate part is that parents don’t seem inclined to send their children outside like they used to—or, alternatively, computers, video games, and improved television programming have made the indoors too delightful for a child to resist. According to a 2004 study from the University of Michigan, the average child in 2002 spent exactly half as much time participating in outdoor activities as did children in 1981. While myopia hasn’t yet reached the levels seen in much of Asian, prevalence in the United States is rising quickly. A 2009 study showed that the prevalence of myopia among Americans between the ages of 12 and 54 surged from 25 percent in the early 1970s to 42 percent around the turn of the millennium.